CDFA Plant Health

Encycloweedia: California Weed Laws

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The following is a digest of the most important laws affecting noxious weeds in California. For the most part, they are derived from the laws for pests in general. The laws are found in the California Food and Agriculture Code. One link to the complete code is

403. The department shall prevent the introduction and spread of injurious insect or animal pests, plant diseases, and noxious weeds.

461. The department may conduct surveys or investigations of any nursery, orchard, vineyard, agricultural commodity, agricultural appliance, farm, or other premises within the state liable to be infested or infected with any pest as defined in Section 5006 or disease, including any infectious, transmissible, and contagious diseases of livestock and poultry, for the purpose of detecting the presence of, or determining the status of, the pest or disease. The director and the county agricultural commissioner shall consult concerning these surveys or investigations and in the conduct or implementation of any control or eradication activity when the provisions of this code provide joint responsibilities in connection with the pest or disease.

5004. "Noxious weed" means any species of plant that is, or is liable to be, troublesome, aggressive, intrusive, detrimental, or destructive to agriculture, silviculture, or important native species, and difficult to control or eradicate, which the director, by regulation, designates to be a noxious weed. In determining whether or not a species shall be designated a noxious weed for the purposes of protecting silviculture or important native plant species, the director shall not make that designation if the designation will be detrimental to agriculture.

5021. Unless otherwise provided, any treatment which may be required pursuant to this division is at the risk and at the expense of the owner or person in charge or in possession of the property which is treated at the time of treatment.

5023. The commissioner, whenever necessary, may enter and make an inspection of any premises, plant, conveyance, or thing in his jurisdiction.

5024. (a) The secretary or the commissioner shall, during the maintenance of any quarantine established by the secretary pursuant to Article 1 (commencing with Section 5301) of Chapter 5, inspect any plant or thing that is, or is liable to be, infested or infected by, or which might act as a carrier of, any pest. The person who conducts the inspection shall not permit any of those plants or things to pass over the quarantine line during the quarantine, except pursuant to a certificate of inspection and release that is signed by that person.

5026. (a) The director may overrule a local agency's ordinance or regulation where that ordinance or regulation would prevent or inhibit an eradication effort. The director may act under this section only when the Governor has declared a state of emergency relating to the eradication effort and the effect of the local ordinance or regulation will be to threaten agriculture on a statewide basis, to materially interfere with the ability of the director or the commissioner to eradicate a pest, or where the pest is of such a nature that it could rapidly spread to other areas beyond the boundaries of the local agency.

5027. Unless otherwise expressly provided, a violation of any provision of this division is a misdemeanor.

5301. The director may establish, maintain, and enforce such quarantine regulations as he deems necessary to protect the agricultural industry of this state from pests. The regulations may establish a quarantine at the boundaries of this state or elsewhere within the state.

5302. The director may make and enforce such regulations as he deems necessary to prevent any plant or thing which is, or is liable to be, infested or infected by, or which might act as a carrier of, any pest, from passing over any quarantine line which is established and proclaimed pursuant to this division.

5306. (a) It is unlawful for any person to refuse to comply with any quarantine regulation which is established by the director pursuant to this division. (b) It is unlawful for any person to possess, propagate, plant, process, sell, or take any other action with regard to a plant or thing subject to a quarantine which has been imported or moved in violation of the quarantine. (c) Notwithstanding Section 5309, any violation of this section is a misdemeanor.

5309. Any violation of this chapter by any person, or an agent of any person, is an infraction, punishable by a fine of not more than one thousand dollars ($1,000) for the first offense. For a second or subsequent offense within three years of a prior conviction of a violation of this chapter, the violation is punishable as a misdemeanor.

5310. (a) In addition to any other penalties prescribed in this division, any person who violates this division or any regulation adopted pursuant to this division is liable civilly in an amount not exceeding ten thousand dollars ($10,000) for each violation. 5321. If the director receives information of the existence of any pest which is not generally distributed within this state, he shall thoroughly investigate the existence and probability of its spread, and the feasibility of its control or eradication.

5322. The director may establish, maintain, and enforce quarantine, eradication, and such other regulations as are in his or her opinion necessary to circumscribe and exterminate or prevent the spread of any pest which is described in Section 5321.

5323. This division and the regulations which are established pursuant to this division are of a statewide interest and concern and are intended to occupy the field. No local jurisdiction shall adopt ordinances, laws, or regulations which prevent, hinder, or delay the effect or application of this division or regulations established pursuant to this division.

5401. Any premises, plants, conveyances or things which are infected or infested with any pest, or premises where any pest is found, are a public nuisance, and shall be prosecuted as such in all actions and proceedings. All remedies which are given by law for the prevention and abatement of a nuisance apply to such a public nuisance.

5402. It is unlawful for any person to maintain such a public nuisance. The remedies which are provided by this article are in addition to any other remedy by way of abatement which is provided in this division.

5403. If, after service of notice pursuant to this chapter a public nuisance is not abated within the time which is specified in the notice, the commissioner shall abate the nuisance by eradicating, controlling, or destroying the pest.

5404. (a) If, after service of the notice pursuant to this chapter, the commissioner determines that the nuisance constitutes an immediate hazard to adjoining or nearby property, and that great or irreparable injury would result from delay until expiration of the time required by law for constructive notice, he or she may forthwith abate the nuisance by eradicating, controlling, or destroying the pest.

5421. If the commissioner finds, after inspection, that any premises, plant, conveyance, or thing in his jurisdiction is infected or infested with any pest, he may in writing notify the record owner or person in charge or possession of the premises, plant, conveyance, or thing, that it is infected or infested with a pest. He may, to his satisfaction, require the person to eradicate, destroy, or control, the pest within the time which is specified in the notice.

5430. …the amount which is incurred or expended by the county in the abatement is a lien on the land against which the expense is chargeable.

5432. If a copy of the notice to abate a public nuisance, as described in Section 5401, is recorded and a copy is served upon or mailed to the holder of any encumbrance of record pursuant to this article, the lien is superior to all encumbrances, existing and future, except liens for taxes and assessments.

5434. Except as provided in Article 3 (commencing with Section 5461) of this chapter, the district attorney of the county which makes payment of the abatement expense shall, within 120 days after the notice which is required by Section 5431 is recorded, commence in the name and for the benefit of such county, an action to foreclose the lien. 5761. The regulations which are adopted pursuant to Article 2 (commencing with Section 5321) of Chapter 5, Part 1 of this division may proclaim any portion of the state to be an eradication area with respect to the pest, prescribe the boundaries of such area, and name the pest and the hosts of the pest which are known to exist within the area, together with the means or methods which are to be used in the eradication or control of such pest.

5762. Any pest with respect to which an eradication area has been proclaimed, and any stages of the pest, its hosts and carriers, and any premises, plants, and things infested or infected or exposed to infestation or infection with such pest or its hosts or carriers, within such area, are public nuisances, which are subject to all laws and remedies which relate to the prevention and abatement of public nuisances.

5763. The director, or the commissioner acting under the supervision and direction of the director, in a summary manner, may disinfect or take such other action, including removal or destruction, with reference to any such public nuisance, which he thinks is necessary.

7201. The director, after investigation and practical survey, may consult with other state and federal agencies having responsibility for forest management and protection of native species and, by proclamation, declare an area within this state to be practically free from any noxious weed, as defined in Section 5004, which is named in the proclamation.

7206. It is unlawful for any person to sell, distribute, or transport into, or within, any weed-free area any seed of any noxious weed of which the area has been declared to be practically free.

7207. It is unlawful for any person that owns or possesses any land within any weed-free area to knowingly permit any noxious weed of which the area has been declared to be practically free, to mature upon his land and disseminate its seed or to propagate itself by other means upon such land, or on the land of another.

7501. It is unlawful for any person to disseminate the seed of any pest within this state.

7502. The enforcement of this chapter is under the supervision of the director. He shall make such regulations as he may deem necessary to properly carry out the provisions of this chapter.